WordPress fix Reply To: CSS editing for my site

Guest

Hi Andrew,
Running windows 7 pro 64bit
Wampserver latest
Theme accelerate by themegrill
with the theme’s own child, they made it
Activated the child, main theme is installed
Go to Appearance-edit
Get the “Heads-up” about using a child, not edit main theme, but it is a child theme.
Cannot use editor, comes back cannot save.
Interestingly enough, did a reinstall of everything BUT used WP4.6.8, and refused the update to 4.9, and can edit child .css.
As an aside, The new idea of flagging CSS errors is good But useless, if you can’t edit them.
Thanks for your time
Grey